Kev xaiv cov ntaub ntawv

	Qee qhov xwm txheej, hom khoom koj yuav hemming yuav pab koj txiav txim siab seb yuav siv cov ntaub ntawv twg.
	Cov ntaub ntawv mos xws li txhuas, tooj dag, txhuas, yas thiab ntoo yuav xav tau cov ntaub ntawv tshwj xeeb lossis cov ntaub qhwv. Cov ntaub ntawv nyuaj heev kuj yuav xav tau cov ntaub ntawv tshwj xeeb. Yog xav paub ntxiv txog yuav ua li cas hardness cuam tshuam rau kev ua ntaub ntawv saib: Hardness yog dab tsi?
	Hauv qab no yog cov lus qhia txog cov ntaub ntawv twg los siv rau cov ntaub ntawv tshwj xeeb.
	Aluminium lossis hlau mos xws li tooj liab Aluminium, millenicut thiab vixen cov ntaub ntawv
	Ceramic los yog iav Cov ntaub ntawv pob zeb diamond
	Hardened hlau Cov ntaub ntawv pob zeb diamond
	kub hlau Rasps
	Hlau, hlau lossis hlau tawv xws li titanium Txhua cov ntaub ntawv (tsis txhob rub)
	Xov Xwm Lead floating cov ntaub ntawv
	yas Rasps
	Tsob ntoo Japanese cov ntaub ntawv thiab rasps